The present invention relates to an exercise wheel and, more particularly, to such an exercise wheel, which is durable in use.
Various exercise wheel designs have been disclosed, and have appeared on the market. Similar designs are seen in U.S. Pat. No. 6,146,318 entitled xe2x80x9cPUSH AND PULL TYPE ROLLER EXERCISERxe2x80x9d; U.S. Pat. No. 6,017,296 entitled xe2x80x9cEXERCISE WHEELxe2x80x9d. The xe2x80x9cEXERCISE WHEELxe2x80x9d of U.S. Pat. No. 6,017,296, as shown in FIG. 9, comprises a housing 51, a grip rod 52 which is put through the housing 51 such that both longitudinal ends thereof are left out in the outside of the housing 51, a main wheel 53 rotatably mounted on the grip rod 52 inside the housing 51, two auxiliary wheels 54 sets pivoted in the housing 51 such that they are linked with the main wheel 53, and at least one elastic recovery device, for example, a torsional spring 56 disposed between the main wheel 53 and the housing 51 for providing the main wheel 53 with a recovery force enabling the main wheel 53 to return to its original angular position. This design of exercise wheel is not durable in use because the torsional spring 56 wears quickly with use and no means is provided to limit the dead point of deformation of the torsional spring 56. Because the main wheel 53 and the auxiliary wheels 54 are gear wheels meshed together, teeth of the main wheel 53 and the auxiliary wheels 54 wear quickly with use and produce much noise during transmission. Further, the gear transmission design of the wheels 53;54 greatly increases the manufacturing cost of the exercise wheel. The design of xe2x80x9cPUSH AND PULL TYPE ROLLER EXERCISERxe2x80x9d of U.S. Pat. No. 6,146,318 has similar drawbacks.
The present invention has been accomplished to provide an exercise wheel, which eliminates the aforesaid drawbacks. It is the main object of the present invention to provide an exercise wheel, which is durable in use. It is another object of the present invention to provide an exercise wheel, which produces less noise during operation. According to one aspect of the present invention, the exercise wheel comprises a housing, a wheel base equipped with two main wheels and a front balance wheel and mounted in the housing, a slide slidably mounted in a longitudinal track in the wheel base, a torsional spring disposed between the slide and the longitudinal track for providing the slide with a recovery force enabling the slide to return to its original position, and a belt connected between a wheel axle, which is rotated with the main wheels to take up/let off the belt when the user reciprocate the exercise wheel on the floor, and the slide. Because the slide is mounted in the longitudinal track and moved to stretch/release the tensile spring, the longitudinal track limits the amount of deformation of the tensile spring. Further, because the invention eliminates the use of gear transmission means, less noise is produced during the operation of the exercise wheel.